HOUSTON -- While George Bush envisioned the one economic summit he will host as a jump-starter for stalled trade talks, his fellow heads of government were transfixed by the notion of showering money on Mikhail Gorbachev.

Consequently, President Bush had to steer a tricky course here. First, deflect the debate over aid to the Soviet Union with warm and fuzzy language. Then, perform the more difficult feat of getting European leaders to order their negotiators at long last to start negotiating on trade-distorting farm subsidies.

What has become clear to Bush advisers, if not to the non-confrontational president himself, is the gap between the American and his European pals. Nor are those differences handled best by the rigid format of these annual get-togethers, grown extravagant and ritualized, of the world's seven richest democracies.

Economic summits were conceived in a desperate search for remedies by the French and Germans in 1975, when the West was demoralized economically and politically. Since the 1981 summit in Ottawa, which greeted newly elected Ronald Reagan with contempt for proposing tax cuts, the philosophical gap between the United States and most other summiteers, especially the continental Europeans, has dominated the sessions.

Bush, not happy with his first such summit in Paris last year, sought ways to make the Houston meeting more relevant. He quickly rejected a proposal to spice it up by inviting Mikhail Gorbachev. Instead, he settled on the more serious goal of saving Uruguay Round trade talks from European intransigence.

Two obstacles loomed. First, the Europeans insisted on protecting their noncompetitive agriculture. Angry Brussels bureaucrats scheduled an emergency briefing here to denounce the presumptuous Americans. ''We cannot apply free trade to agriculture,'' ordained Guy Legros, the European Community's agriculture chief.

The second barrier was posed by the gravitation of these summits toward the day's headline -- currently, the Soviet crisis. West German Helmut Kohl's Realpolitik of offering aid in return for Kremlin approval of his country's unification was buttressed by dreamy socialist ideals of French President Francois Mitterrand and the faith of all -- Bush included -- that Western aid can save Gorbachev.

But since outright aid would be a colossal waste, how could Bush stave off Kohl and still get his help on the Uruguay Round? Mainly by keeping private pressure on Kohl.

Certainly not by summiteers debating agricultural policy. They all delivered set speeches on trade in their opening closed-door session Monday, then never mentioned the subject at a private (no aides) dinner that night. The farm issue was not on Tuesday's agenda, leaving it for today's wrap-up session before the final communique'.

U.S. officials here publicly promoted free trade, with Secretary of Agriculture Clayton Yeutter calling the Uruguay Round ''10 times as important to the economy of the world'' as helping Moscow. Bush circulated language on Monday night calling for a study of Soviet aid by the International Monetary Fund and the World Bank.

Bush's differences with fellow summiteers transcend these issues. Pragmatist though he is, the president's language is geared more to free markets than any other head of state except Britain's Margaret Thatcher. A U.S. draft requiring more reform by China to restore World Bank loans was viewed by others as too harsh. White House Chief of Staff John Sununu publicly spanked the Germans for environmental hype.

Such disputes might be better worked out in private diplomacy -- particularly with Bush as president. On the telephone to Kohl several times a week, he scarcely needs formal ''bilateral'' sessions with Kohl in Houston. Six of the seven heads were together in London last week for the NATO summit, and the seventh -- Japan's Toshiki Kaifu -- requires no get-acquainted session with Bush.

All the time and money spent in Houston will be deemed worthwhile by summit defenders if Europeans start scrapping farm subsidies in a successful Uruguay Round at year's end. But it will be a stretch to attribute that triumph to a process that may well widen rather than narrow the U.S. philosophical gap with Europe.